Thousands of employees at some of the largest financial institutions in the country stood in line to get to work, patiently showing identification tags.

"You realize that's the world you live in, and you deal with it," said Kenneth Polcari, a trader at the New York Stock Exchange, one of five buildings the government says al-Qaida operatives have studied.

Recent intelligence — including photos, drawings and written documents — indicates terrorists have focused on the stock exchange and The Citigroup Center in Manhattan, the International Monetary Fund and World Bank buildings in Washington and Prudential Financial Inc.'s headquarters in Newark, N.J., officials said.

"What we're talking about here is a very serious matter based on solid intelligence," President Bush said.

Employees at the targeted buildings began their work week with extra checks of bags and identification, added barricades and police officers outside.

Police closed Manhattan streets around Grand Central Terminal and banned trucks from some bridges and tunnels. Trucks passing landmarks or traveling on major thoroughfares also were subject to random searches. In some cases, truck drivers were asked to show documentation on where they were headed.

Police said the restrictions would remain in effect Tuesday and would be reviewed daily.

New York Mayor Michael Bloomberg and Gov. George Pataki rang the opening bell at the stock exchange to show confidence in the city's security response.

"America and New Yorkers are pulling together here, and they're not going to be cowed," Bloomberg said.

He and Pataki visited the Citigroup building with First Lady Laura Bush and her twin daughters in the afternoon. The mayor also was to meet there Tuesday morning with Department of Homeland Security Secretary Tom Ridge and financial executives, a mayoral spokesman said.

"I want to thank people for coming to work. I'm really glad to be here today," the first lady said as she stopped to chat with some office workers at the 59-story skyscraper in midtown Manhattan.

Peter Manzi, a banker from suburban Long Island, said seeing the high-profile entourage at Citigroup was "very encouraging."

"You can't let the bad guys win," he said after briefly meeting the president's family.

Authorities said the terror intelligence did not specify timing of an attack.

"Since 9/11 I think any of us who work here know we're a target," said Donna Mendez, who works on the 27th floor. "We're not going to let (terrorists) stop us from doing what we do. That's what they want."

In Newark, officials set up concrete barriers and police teams around the 24-story Prudential building, where about 1,000 employees work. They showed identification to get into the building and its underground parking garage.

Greater security was also more visible in the nation's capital, where authorities have already fortified key buildings against terrorism. Capitol Hill was filled with tourists on a busy summer morning while police went on 12-hour, six-day-a-week shifts in response to the heightened security alert, spokeswoman Sgt. Contricia Ford said.

Police checked identity cards as employees filed in to the World Bank headquarters; inside, security guards checked them again. Across the street, guards at the International Monetary Fund swept the underside of cars with detecting devices as they entered the garage.

"I'm concerned, but we have to carry on as normal," said IMF employee Shirley Davies.

Washington, D.C., police chief Charles Ramsey said the upgraded security is likely to continue at least until after the November election.

None of the newly discovered terror intelligence involved specific threats to the Republican convention in Manhattan or the election process, authorities said Monday. The warnings won't affect security for the convention, which begins Aug. 30.

"It's not going to require any significant shift," said Paul Browne, chief spokesman for the New York Police Department.

Security plans for the convention already included extra protection for Wall Street and other financial centers — long considered possible targets for terrorists.

Ridge on Sunday raised the terror threat level for financial institutions in the three cities to orange — high alert, the second highest level on the government's five-point spectrum. Elsewhere, he said, the alert would remain at yellow, or elevated.

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